Motion and Projectiles Homework-Due tommorow

Extended Writing Task: Freefall

Two identical steel balls are released from rest above cylinders containing oil as shown in the diagram below.The balls travel vertically until they reach the bottom of the cylinder. The graph below is the velocity-time graph for steel ball A.

Diagram:
-steel ball A is above cylinder container 1 with oil filled to the top
-steel ball B is above cylinder container 2 which has oil filled to half way

Velocity-time Graph:
in the graph steel ball A has a curved line in which as the time goes on the velocity rate decreases but there is still more velocity with more time but less and less until a certain point where the reaction stops.At the end of the curved line there is a line going downwards.

Describe and explain how the motion of steel balls A and B will differ and why.Your answer should include:
-How the velocity and acceleration of steel ball A and B vary with time
-An account of the forces acting and their sizes
-A sketch of the velocity-time graph that would represent the motion of steel ball B (you may wish to draw this over the graph above)

Continue this task on lined paper writing with good English and attach it behind this sheet.

Write as much as you can.

Please help as I'm stuck on this question with no clue and have gone over it many times.
All i have come up with is:
The more the oil the less the friction so the faster the ball moves in the oil so steel ball A would be faster as the oil is filled to the top. Steel ball b first goes through air which has more friction than oil so is slower.

I have no idea if its right or wrong but please tell me the correction and please help with the rest of the whole answer

3 answers

Unless your oil is magic, it may be slippery but has far more resistance (viscosity) than air. In fact on the scale you are talking about I think the air is effectively friction less and the steel ball being thousands of times as dense as air will fall at about constant acceleration, g, about 9.81 m/s^2
The speed of the steel ball will therefore be proportional to time and distance to time squared in air. That means as long aas it is in air the oath will be parabolic, getting steeper and steeper.

NOW when the ball hits oil, suddenly the world changes. It hits with the same initial speed as the first ball at that height, but rapidly reaches what we all "terminal velocity". That is when the friction up equals the weight down and the speed becomes constant. From then on height versus time is a straight line.
Would ball B be faster then, as oil has more friction than air so make the ball slower?

Thank you, could you also help with the things you have to include which is:

Describe and explain how the motion of steel balls A and B will differ and why.Your answer should include:

-How the velocity and acceleration of steel ball A and B vary with time
-An account of the forces acting and their sizes
-A sketch of the velocity-time graph that would represent the motion of steel ball B (you may wish to draw this over the graph above)
Also what do you mean by oath will be parabolic?